Safety arrangements for screws are known in the state of the art. For example, DE 296 21 267 U1 teaches a screw terminal in which the screw head is covered by a cover housing except for a screwdriver opening. Ribs are provided that are formed in axial direction in the cover housing and distributed over the circumference which ribs have an extremely small distance relative to each other that is smaller than the diameter of the screw head. In this state of the art, when the terminal screw is screwed in the ribs are deformed and abraded. The screw is securely received in the cover housing conditioned by the elasticity of the ribs.
This known solution has the disadvantage, however, that the ribs extending in the longitudinal direction of the screw on the cover housing must be manufactured in precise coordination with the screw to be used in order to ensure a reliable functioning.
The tolerances to be observed are dimensioned very closely since the ribs must on the one hand make it possible to screw the screw in without destroying the cover housing by overexpansion, whereas on the other hand the screw must be securely held after being introduced. This results in the need to exactly observe the measurements and brings about a high manufacturing cost and therefore greater expenses during the production.
DE 30 28 958 C2 teaches a serial terminal in which the terminal screw is arranged in a shaft of a body in such a manner that it can be lowered. A profiling is provided in the shaft that is elastically deformed when the screw is screwed in and when the head is passed over. After the profiling is passed over the profiling deforms back only partially in an elastic manner so that the profiling designed as a bead functions as a safety.
Even in the case of this arrangement known from the state of the art a very close coordination of the constructional measurements and the observance of very close manufacturing tolerances are required in order to reliably hinder a destruction of the component during screwing in and the loss of the inserted screw.
Furthermore, apparatuses are known from the state of the art in which a circumferential rib is provided in the shaft receiving the screw which rib has a smaller free inside diameter than the greatest outside diameter of the screw head. If a screw is introduced into such a shaft and moved past the annular rib, it is reliably received in the shaft. However, even this functioning solution requires a precise coordination of the manufacturing tolerances since the screw flange can otherwise be torn off during an automatic mounting of the screw if the expansion forces exceed the stability of the component when the screw head passes through.
Such a system functions during a slow assembly by hand or also by exactly observing the tolerances, which, however, again brings about a significant technical manufacturing cost and therefore higher expenses.
Given the cited state of the art, the present invention therefore has the problem of making available a device for reliably receiving a screw on an electrical component and in particular on a connecting terminal with greater manufacturing tolerances being admissible and a high reliability of prevention against loss can be achieved.